This is a very common question we hear in physiotherapy. There is one misconception which exists – ice for 24 to 48 hours and then heat. This is wrong for most situations people find themselves in following an injury. You can almost never go wrong with ice, but you can easily go wrong with heat. We will explain what you should do and most importantly – why.

When a person suffers an injury, swelling is the result. Swelling occurs due to blood vessels being damaged and from fluid (along with cells, proteins etc…) being drawn out of the blood vessels towards the injured tissues. In addition chemicals are released from cells which cause the blood vessels to open up and bring more blood to the injured area.

When a blood vessel is damaged, bleeding is the result. This will stop when the blood clots, but continued movement will disrupt the clot and bleeding will continue. Bruising is the result you see on the surface. One thing is for sure – we have all had a bruise. We all know that bruising is painful to a degree. Your body is normally very happy when the blood is in the blood vessels. When you have an injury where blood leaks out into the tissues, this blood irritates the area and causes pain. We can see that limiting this process would be helpful.

Swelling is a normal process and is how your body starts the healing process. This same process happens no matter how small or how big the injury, the only difference is the quantity of swelling. Some people swell more than others. Some people stop moving as soon as they get hurt. Some people try to keep going and say they will deal with it later… Too much swelling is not good.

There are five signs and symptoms of swelling; pain (from mechanical and chemical irritation of the nerve endings), redness (from increased circulation to the area), heat (from increased metabolism and blood flow – your skin and extremities are cooler than the blood in your body), decreased  movement (the swelling stiffens up the tissues and helps to act like a splint to protect the area so it can start to heal) and decreased function (you are not able to do normal activities due to the loss of movement).

Now that an injury has happened there is a choice to be made – do you apply ice or heat? Our goal should be to control swelling and pain. ICE is the answer and here is why. Ice will cause the blood vessels to narrow and decrease the quantity of blood flowing into the injured area. Ice will decrease the pain. Ice will decrease the need for oxygen by the tissues. Ice will prevent or decrease the amount of swelling which will happen, ice will not decrease swelling which is already present. There are many other benefits of icing which we will not discuss here.

In today’s society – people do not just sit still. They move around a great deal and this movement, no matter how small, will irritate the injury. A perfect example is an ankle sprain. People hate using crutches so they keep walking and limping on the ankle. Even a small amount of walking can keep the injured area quite irritated. Because of this irritation, ICE is the treatment which continues to be necessary over many days or even weeks. The same rationale can be applied to any injury where the person is moving and using the injured area.

Now imagine the opposite. If the injured area was heated, more blood flow would come into the area, there would be more bleeding, more irritation, more swelling and a much longer healing time. In our above example of the ankle sprain, a 4-8 week process suddenly becomes 3 months or even more.

When we deal with injuries, Ice is never used alone, it is combined with other treatments so we can maximize the effects and minimize the healing time. You may hear R.I.C.E. (rest, ice, compression, elevation) used when we talk about acute injuries. Sometimes you may hear P.R.I.C.E. – where the “P” is added on to represent prevention. We try to prevent further injury and irritation to the already injured area.